The present invention is an improvement on U.S. Pat. No. 3,721,297 for Method For Cleaning Wells, invented by Robert D. Challacombe, one of the inventors of the present invention. Arrangements described in the U.S. Pat. No. 3,721,297 have been used with significant and wide-spread success for many years. However, the apparatus disclosed in this patent is relatively complex and costly to manufacture. Particular molding of specific parts, assembly of various internal elements, and arrangements for initiating detonation in desired sequences require significant manufacturing time and effort and relatively complex assembly procedures. Although overall reliability has been shown to be excellent, improvement is always desired.
Government regulations concerning safety of handling and transport of explosive materials require that parts cannot be armed during shipment. Such regulations, accordingly, have required changes in the mode of assembly and handling of the prior apparatus, thus adding still further complexity and expense.
Accordingly, it is an object of the present invention to provide methods and apparatus for cleaning of wells which avoid or minimize above-mentioned problems.